Can't get my work to show on the cube
Here are the 4 viewport shading modes: Wireframe / Solid / Material / Rendered. Use the shortcut Z to switch from a mode to another.

Wireframe to see the topology of your object, Solid to see the same but with a basic grey shade, these 2 first modes are ideal to work and move your objects, use AtlZ to enable transparency. Material to work on your materials, it won't take into account the lightings, so it won't give a good idea of your render. And at last, the Rendered mode, which is how you'll see your objects when rendered.